Multiple Mailboxes with Multi-Mount Support in Type 4 Foundation

Report Number(s): 0-6946-R2

Description: The mailbox configuration evaluated in this test consisted of four mailboxes (two large and two medium) mounted at a height of 42 inches above grade to a semi-circular multiple mount support post that was installed in a socket embedded in a concrete footing. Two large Stanley No. 2 mailboxes (Model #ST200B00) from Solar Group, Inc., a division of Gibraltar Industries, were attached at the two inside positions of the four mounting positions on the support post. The large Stanley mailboxes were approximately 15 inches tall × 11½ inches wide × 24¾ inches deep and weighed 11 lb. Two medium Elite No. 1-A mailboxes (Model #E1600B00) from Solar Group, Inc., a division of Gibraltar Industries, were attached at the two outside mounting positions on the multiple-mount support. The medium Elite mailboxes were approximately 11 inches tall × 8¾ inches wide × 21½ inches deep and weighed 7 lb. Attachment of each mailbox to the horizontal segment of the multiple-mount support post was accomplished using a mailbox bracket with a vertical steel tube sleeve (DHT #161443), two extension brackets (DHT #148938), and associated SAE grade 5 bolts, nuts, and washers. The four mailboxes were supported with a TxDOT multiple-mount post (DHT #164116) fabricated from 2-inch nominal, 16 gauge (2.375-inch outside diameter × 0.065-inch wall thickness) thin wall ASTM A513 Type 5 DOM steel tubing. The support post incorporated a vertical section that inserted into a foundation sleeve with two small plates that controlled the embedment depth into the socket, a U-shaped section centered above the vertical section, and a horizontal section near the top. The ends of the semi-circular section of the support extended above the horizontal member to provide the outer connection points for mailbox attachment. There were two additional short vertical pipe sections attached to the interior of the horizontal member to provide two additional interior mailbox attachment points. The leg of the multiple-mount support post was inserted approximately 12 inches into a Type 4 foundation socket (DHT #160891) and secured with a tapered HDPE wedge (DHT #160892) on the field side of the mailbox. The socket was embedded flush to the top of a nonreinforced concrete foundation that measured approximately 12 inches in diameter × 30 inches deep. The concrete was specified as TxDOT Class B having a minimum 28-day unconfined compressive strength of 2000 psi. The total mass of the four mailboxes, connection hardware, and support post assembly was 70 lb

Test Level: 3

MASH Test Number: 3-61

Proprietary/Non-proprietary: Non-proprietary

Pass/Fail: Pass

Evaluation: Full-Scale Crash Testing

Sponsor: Texas Department of Transportation